BYRNES: CYCLOPS OF FRESH WATER. 



25 



Foot No 



Ramus, Outer or Inner 



Outer Spines 



Apical Spines 



Apical Setio 



Inner Seta; 



^seta 



This armature agrees with that of C. parcits. The rudimentary 

 fifth foot is two-jointed. The basal joint is very short and narrow 

 and bears an outer seta, often without barbs. The distal segment 

 is long and narrow and bears two terminal hairs resembling that 

 on the basal segment in general character and in length (Fig 3, 

 Plate X.). 



Cyclops Biciispidahis, Forbes (Plate X.). 



This species w^as found at Cypress Hills, Long Island, and w^as 

 collected with C. Aniericanus, Marsh (C. iiisecfiis, Forbes) and 

 C. parais (Herrick). 



It belongs to the same general type as C. pnlchellus, but is larger 

 and dififers somewhat in the shape of the cephalo-thorax, in the 

 length of the antennae, in the character of the fifth foot and in the 

 outline of the receptaculum seminis. In the armature of the swim- 

 ming feet, the species also agrees with C. parens. 



In the later stages of the adult condition there are seventeen 

 segments in the antennre but there may be only thirteen segments, 

 even when the form is sexually mature as shown in Fig. 5, 

 Plate X. 



The segments of the fifth foot agree very closely with corre- 

 sponding segments in C. pnlchellus but the armature on the inner 

 angle of the distal segment dififers in the presence of a strongly 

 serrated spine of about half the length of the adjacent seta. 



The receptaculum seminis has a low wide arch directed anteriorly. 

 It suggests the receptaculum of C. pnlchellus but the outlines drawn 

 dififer, owing partly to the fact that it is full in the specimen drawn 

 of C. bicuspidatus, and partly empty in the specimen of C. pal- 



